Mercury acetylide-silver nitrate complex and process of making same



Patented July 5, 1949 UNITED STATES PATENT OFFICE MERCURY ACETYLIDE-SILVER NITRATE COMPLEX AND PROCESS OF MAKING SAME No Drawing. Application February 7, 1946, Serial No. 646,186

4 Claims. 1 This invention relates to acetylene compounds. More particularly the invention relates to a complex compound formed by the reaction of acetylene with silver nitrate and mercuric nitrate.

A strong silver nitrate solution reacts readilywith acetylene to form a silver acetylide compound, Ag2C26AgNO3. This silver acetylide com- Pound is quite soluble in the mother liquor (AgNOs), the solubility increasing as the concentration of the liquor increases. In fact a strong silver nitrate solution will easily become supersaturated with the silver acetylide and the acetylide may be held in a supersaturated state for an indefinite period without precipitation.

Coke oven and coal gas contain substantial amounts of acetylene and olefines. Strong silver nitrate solution is a good absorbent for the olefines so that the silver nitrate will absorb the olefines and react with acetylene. The olefines may be removed from the silver nitrate solution by heating it, but an ordinary amount of heating will not drive out the silver acetylide compound from the solution. We have found that the silver acetylide compound, Ag2C26AgNO3 may be completely precipitated from a silver nitrate solution with mercuric nitrate Hg(NO3)2. The mercuric nitrate forms a new product with the silver acetylide, a complex white crystalline product appearing to have the composition I-IgCzBAgNOa. This complex mercury-silver-acetylene compound may be separated from the silver nitrate solution by decantation or filtration.

The primary object of the present invention is to provide a new compound HgC2.3AgNO3, and a process of producing this complex compound.

The silver acetylide compound AgzCzGAgNOs is preferably made by adding acetylene (C2H2) to a 31% by weight solution of anhydrous silver nitrate dissolved in aqueous one normal nitric acid. If the solubility ratios are maintained, a clear solution will result.

To separate the silver acetylide from this solution a sufiicient quantity of mercuric nitrate to provide mercury to replace the silver of the silver acetylide Ag'zCaGAgNOs, is added to the silver acetylide solution. The mercury acetylide-silver complex is a very fine-grained white precipitate which is not soluble in the mother liquor and can be separated therefrom by filtration. The individual crystals of the precipitate are scarcely distinguishable at a magnification of 240 diameters. If the mercury-silver complex is separated from the solution and heated, the material will decompose but the decomposition is not explosive in nature. If the decomposed product is further heated metallic silver and mercury will separate. If the paste is suspended in a dilute solution of nitric acid and mercuric nitrate or in a portion of the original silver nitrate solution containin an excess of mercuric nitrate and heated at or near the boiling point, the acetylene is completely decomposed, apparently to CO2 and water together with the brown fumes of oxides of nitrogen.

The mercury acetylide-silver complex has a distinct commercial value in that it affords a cheap and effective means by which acetylene may be removed from gas, and an effective precipitant by which silver acetylide AgzCzBAgNOs, may be separated from a silver nitrate absorption solution. With the process of absorbing the acetylene and then decomposing the acetylide compound, the acetylene may be effectively removed from the gas and destroyed without danger of explosion.

The preferred form of the invention havin been thus described, what is claimed as new is:

1. A mercury acetylide-silver complex 2. A process of making HgCa3AgNO3 comprising: treating AgzCzfiAgNoa in a strong silver nitrate in acid solution with mercuric nitrate to replace the silver in the AgzCz radical with mercury.

3. A process of making HgC2.3AgNO3 comprising: absorbing acetylene in a strong silver nitrate solution containing nitric acid to form AgzCzGAgNOs treating the AgaCzfiAgNOs with mercuric nitrate to precipitate HgCa3AgNO3 and filtering to separate the HgCz.3AgNO3.

4. A process of making a mercury acetylidesilver complex HgC2.3AgNO3 comprising treating Ag2Cz.6AgNOa with sufilcient mercuric nitrate Hg(NO3)z in nitric acid solution to supply the mercury required to replace the silver of the Ag2C2 radical of the complex.

JOSEPH A. SHAW. ELTON FISHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,082,569 Carothers et al. June 1, 1937 2,150,349 Van Peski et al. Mar. 14, 1939 OTHER REFERENCES Bull. Soc. Ind. (deR'ouen) vol. 34, p. 417, Duboso (1907) 

